iPhone acted very very weird, more than twice (dodgy controls, black screen)

iPhone 8, iOS 13.1.3

Is my phone being hacked??

Some weird software bug?

What happened is that I'd do double tap home button view, and try to swipe windows away (swiped up). The windows didn't do their usual swipe up and go away. They stayed where your finger left off. I tried swiping up other windows, and the first window, following other windows, were stuck on the upswipe like the previous. I could position them left right up or down, individually, but couldn't get them to go away. I could get out of that view once or twice, it would do the same thing once back on that view, then I couldn't get out of it, then could, then I was on the home screen. The phone then became unresponsive. I looked at the top of the screen and it showed the Lock icon. It was Locked.

Then, went to a black screen. It was still on. I could tap the home button, but nothing displayed.

Black screen. I tried turning it off to no avail, using power button and home button power button combo (which I don't think works anymore). Nothing. I could feel it was still on, because the home button made its vibrate feel when I pressed like normal.

Then, 1 minute 30 seconds later, out of nowhere, the login screen appears, but with a gray background instead. It didn't just *appear* quickly like normal, it appeared slowly. It took 2 1/2 seconds to go from black to this new login screen. A slow progression from black screen to this gray lock screen, and I saw more than 4 characters. I saw more than 4 needed passcode inputs, more like 6, I mean I think I saw that.

I pressed my thumb and it unlocked. I tried doing a screenshot but it unlocked too quickly for me to press the power button for screenshot to work.

This has happened once or twice before, but without the login thing and black screen. Just the crazily acting multi-window view.

I had no VPN connected, not very many things running. I keep most programs disabled for background. I don't remember what I was doing while it happened. Maybe 3 things running.

Happened once maybe 5 days ago, a few days before that.

It's very weird. Has anyone else had this happen to them?

Again iPhone 8, iOS 13.1.3